<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>call</title>
</head>

<body>
    <div>打开浏览器控制台查看结果</div>
    <script>
        const call =
            (key, ...args) =>
                context =>
                    context[key](...args);
        Promise.resolve([1, 2, 3])
            .then(call('map', x => 2 * x))
            .then(console.log); // [ 2, 4, 6 ]
        const map = call.bind(null, 'map');
        Promise.resolve([1, 2, 3])
            .then(map(x => 2 * x))
            .then(console.log); // [ 2, 4, 6 ]
    </script>
</body>

</html>